I have compiled some of the best free media players for Linux OS to play almost any video, audio formats you will ever need as a Linux user.
VLC media player is a cross-platform open-source multimedia framework, player and server. VLC media player is a highly portable multimedia player and multimedia framework capable of reading most audio and video formats (MPEG-2, MPEG-4, H.264, DivX, MPEG-1, mp3, ogg, aac ...) as well as DVDs, Audio CDs VCDs, and various streaming protocols. See the full features list. It can also be used as a media converter or a server to stream in unicast or multicast in IPv4 or IPv6 on networks.
xine is a free multimedia player. It plays back CDs, DVDs, and VCDs. It also decodes multimedia files like AVI, MOV, WMV, and MP3 from local disk drives, and displays multimedia streamed over the Internet. It interprets many of the most common multimedia formats available – and some of the most uncommon formats, too.
Totem is the official movie player of the GNOME desktop environment based on GStreamer. It features a playlist, a full-screen mode, seek and volume controls, as well as keyboard navigation. It comes with added functionality such as: Video thumbnailer for the file manager, Nautilus properties tab, Mozilla (Firefox) plugin to view movies inside your browser (in development), Webcam utility (in development) and more.
The Helix Player is an open source media player for Linux, Solaris, and Symbian based on the Helix DNA Client media engine. More operating system versions are currently in development.
RealPlayer for Linux allows you to play more video, including popular Windows Media files, RealMedia files and more. Get instant access to your favorite songs or video. Easily create, save, edit and manage different playlists for any event or mood. Updated multi-channel stereo sound allows you to enjoy 5-channel audio plus a dedicated sub-woofer channel for streaming or playback through either your ALSA or OSS sound system. Need to take a break from a live stream? Just click pause. Perfect Play automatically buffers streaming content. So you can pause, rewind and fast-forward through live broadcasts without missing a thing.
MPlayer is a movie player which runs on many systems. It plays most MPEG/VOB, AVI, Ogg/OGM, VIVO, ASF/WMA/WMV, QT/MOV/MP4, RealMedia, Matroska, NUT, NuppelVideo, FLI, YUV4MPEG, FILM, RoQ, PVA files, supported by many native, XAnim, and Win32 DLL codecs. You can watch VideoCD, SVCD, DVD, 3ivx, DivX 3/4/5, WMV and even H.264 movies. Another great feature of MPlayer is the wide range of supported output drivers. It works with X11, Xv, DGA, OpenGL, SVGAlib, fbdev, AAlib, DirectFB, but you can use GGI, SDL (and this way all their drivers), VESA (on every VESA compatible card, even without X11!) and some low level card-specific drivers (for Matrox, 3Dfx and ATI), too! Most of them support software or hardware scaling, so you can enjoy movies in fullscreen. MPlayer supports displaying through some hardware MPEG decoder boards, such as the Siemens DVB, DXR2 and DXR3/Hollywood+. MPlayer has an onscreen display (OSD) for status information, nice big antialiased shaded subtitles and visual feedback for keyboard controls. European/ISO 8859-1,2 (Hungarian, English, Czech, etc), Cyrillic and Korean fonts are supported along with 12 subtitle formats (MicroDVD, SubRip, OGM, SubViewer, Sami, VPlayer, RT, SSA, AQTitle, JACOsub, PJS and our own: MPsub). DVD subtitles (SPU streams, VOBsub and Closed Captions) are supported as well.
So, what's your favorite media player?